Ketogenic diet-induced prurigo pigmentosa: a rising association.

Prurigo pigmentosa (PP) is an uncommon inflammatory dermatosis first described in 1971. It is characterized by recurrent crops of pruritic erythematous papulovesicles that resolve with a macular reticulated hyperpigmentation. The exact etiology is yet to be determined, however with the expanded application of the ketogenic diet (KD) in recent years, conditions accompanied with ketosis are more commonly being described in association with PP. Antibiotics as well as resolution of ketosis can effectively treat the dermatitis. Given the publicity and growing popularity of the ketogenic diet and numerous references to the "Keto-Rash" on social media, we reviewed the KD-induced PP cases to raise awareness of this increasingly recognized entity and provide an update to clinicians, particularly dermatologists, regarding this possible side effect of KD.